Propolis with High Flavonoid Content Collected by Honey Bees from Acacia
Honey bees, Apis mellifera var ligustica, on Kangaroo
Island, Australia, were found to collect propolis from the sticky exudate on
the stem shoots and seed pods of an Australian endemic plant, Acacia paradoxa.
Extracts of the plant stem shoots and seed pods, the
propolis carried on the legs of bees and freshly collected propolis in hives
contained major flavonoid components consisting of 2',3',4'-trimethoxychalcone,
5,7-dihydroxy-2,3-dihydroflavonol 3-acetate (pinobanksin 3-acetate) and
5,7-dihydroxy-6-methoxy-2,3-dihydroflavonol 3-acetate, a substance not
previously characterized. HPLC and (1)H NMR analyses of the propolis and plant
extracts indicated smaller amounts of other flavonoids.
A survey of propolis samples from 47 apiary sites widely
distributed on Kangaroo Island showed that 15 samples from 6 sites were largely
sourced from A. paradoxa.